Table 2. Analysis of polyamine content in different Shigella strains.

	E. coli	S. flexneri		S. boydii		S. sonnei		S. dysenteriae
polyamine	MG1655	M90T	SfZM49	Sb483	Sb485	SsIP3	SsIP4	Sd96.29	Sd4105.65
N-SPD	8.2±0.9	n.d.	n.d.	n.d.	n.d.	n.d.	n.d.	n.d.	n.d.
PUT	38.5±2.5	30.8±0.8	21.6±1.2	25.6±1.3	24.8±1.5	17.8±0.9	32.4±1.3	44.5±2.1	25.4±1.0
CAD	7.6±0.7	n.d.	n.d.	n.d.	n.d.	n.d.	n.d.	n.d.	n.d.
SPD	8.6±1.1	18.7±0.5	18.6±0.9	17.4±0.7	22.4±0.9	23.1±0.6	27.5±0.5	22.2±0.8	25.3±0.7

Values reported are in nmol per mg of total proteins and represent the average ± standard deviations (n.d. = not detected). N-SPD: Acetyl spermidine; PUT: Putrescine; CAD: Cadaverine; SPD: spermidine.